Conductive keratoplasty for the correction of hyperopia

Trans Am Ophthalmol Soc. 2001;99:79-84; discussion 84-7.

Abstract

Background/purpose: Conductive keratoplasty (CK) is a surgical technique that delivers radio frequency (350 kHz) current directly into the corneal stroma through a Keratoplasty tip inserted into the peripheral cornea at 8 to 32 treatment points. A full circle of CK spots produces a cinching effect that increases the curvature of the central cornea, thereby decreasing hyperopia. We report here the 12-month results of a 2-year, prospective, multicenter US clinical trial conducted to evaluate the efficacy, safety, and stability of CK.

Methods: A total of 233 patients (401 eyes) with preoperative hyperopia of +0.75 to +3.00 D and < or = 0.75 D of astigmatism (mean preoperative manifest refractive spherical equivalent = +1.76 D +/- 0.60) were enrolled into the study at 13 centers and underwent CK treatment.

Results: Twelve-month postoperative data are available on 203 eyes for safety and stability and 171 eyes for safety, stability, and efficacy. A total of 91% had uncorrected visual acuity (UCVA) of 20/40 or better, and 51% had UCVA of 20/20 or better. Manifest refractive spherical equivalent was within +/- 0.50 D in 58%, within +/- 1.00 D in 91%, and within +/- 2.00 D in 99%. The mean change in residual refraction was 0.26 D +/- 0.49 between 3 and 6 months, 0.09 D +/- 0.37 between 6 and 9 months, and 0.13 D +/- 0.39 between 9 and 12 months.

Conclusions: One-year data show safety and efficacy of CK in the treatment of hyperopia. Changes in residual refractive error after CK appeared to be small, suggesting that a stable refraction could be achieved by 6 months.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Astigmatism / surgery
  • Corneal Stroma / physiopathology
  • Corneal Stroma / surgery*
  • Electrocoagulation / methods*
  • Female
  • Humans
  • Hyperopia / physiopathology
  • Hyperopia / surgery*
  • Male
  • Middle Aged
  • Prospective Studies
  • Refraction, Ocular
  • Safety
  • Treatment Outcome
  • Visual Acuity